Some people prefer to filter tap water to remove unwanted impurities, tastes, heavy metals and other toxins. Moreover, when collecting water from a natural, untreated source, such as a lake or a stream, or when traveling in a foreign country that does not treat its tap water, it is important to either filter or treat water for microbial contamination.
Tap water is currently filtered using several different kinds of filtering systems, for example, faucet attachments, refrigerator filter systems, or pitcher or basin-type drip filtration system, from which a user may pour filtered water from the filter systems into his or her cup. Natural, untreated water is typically filtered using a hand-held, filter pump that typically uses vacuum pressure to draw water into the filter. Improved filter assemblies using positive pressure are desirable because drip filtering processes can take a long time and vacuum filtering processes can be hard work for the user.
Positive pressure coffee and tea presses having a single container generally include a plunger received in an outer container. The plunger typically includes a screen filter mounted at the end of a shaft. Hot water is mixed with coffee grounds in the container, and the shaft is pressed down by the user into the container. As the shaft is pressed down, the screen filter presses the coffee grounds to the bottom of the container, while allowing the filtered coffee to pass through the screen to the top of the container. Depending on the tightness of the fit of the screen filter in the container, some grounds may pass to the filtered coffee around the outer perimeter of the screen filter, resulting in undesirable coffee grounds in the user's coffee. Because of the likeliness of contamination in the filtered coffee, a “coffee-press” type water filter is not a good design for water filtration.
Therefore, there exists a need for an improved positive-pressure filter assembly that can improve the experience for a user in filtering water, coffee, and other liquids. There also exists a need for other improvements in container assemblies, such as improved lid assemblies.